Answer:
x=5/2 and -3
Step-by-step explanation:
2x^2 + x = 15.
Subtract 15 from each side
2x^2 + x - 15 =0
Factor
(2x+a ) (x+b ) =0
We need the number to multiply to -15
-1 * 15 -3 *5 -5* 3 -15*1
1* -15 3 * -5 5 * -3 15 * -1
FOIL
2b+a = 1
Take the second number *2 and add the first number . It needs to equal 1
2*15 -1 no
2*5 -3 no
2*3 -5 = 1 yes
(-5 ,3 is the pair)
(2x -5) (x+3) = 0
Using the zero product property
2x-5 = 0 x+3 =0
2x=5 x=-3
x = 5/2 x=-3
